I installed that version and things appear to be fine so far. But I did notice that the Library now seems to be a panel that appears on top of my current workspace rather than appearing along the left side in a new column pushing my workspace to the right.

I'm not sure how I feel about it overlapping my workspace. My first response was to try to figure out how to remove that "feature" but that could possibly be because I instinctively don't like change. ;-) I'll have to think about that a bit more to see if I like that or not.

This has been there since version 10.0. You can now open your library as a zone or popover. Depending on your settings in Preferences -> Appearance -> "Always Show Library as Popover", it will default to either zone or popover. You can then hold down the shift key to get the other one.

However, if there isn't room to open it as a zone, it will always be a popover, and this is what I imagine is happening for you now. Check to see that you don't have any zones or panes that are so narrow they can't get any thinner.